X-ray analysis techniques have been some of the most significant developments in twentieth-century science and technology. The use of x-ray diffraction, spectroscopy, imaging, and other x-ray analysis techniques has led to a profound increase in knowledge in virtually all scientific fields.
One existing class of surface analysis is based on diffraction of x-rays directed toward a sample. The diffracted radiation can be detected and various physical properties, including crystalline structure and phase, and surface texture, can be algorithmically determined. These measurements can be used for process monitoring in a wide variety of applications, including the manufacture of semiconductors, pharmaceuticals, specialty metals and coatings, building materials, and other crystalline structures.
Conventionally, this measurement and analysis process required the detection of diffracted x-ray information from multiple locations relative to the sample in a laboratory environment. Conventional diffraction systems are large, expensive and prone to reliability problems. Their size, cost, and performance limit their use to these off-line “laboratory” settings.
There is a strong drive in the market for applying this technology to real-time process monitoring—allowing real-time process control. In many manufacturing environments, real-time process monitoring and feedback eliminates the need to transport samples to a lab to undergo testing. Real-time process monitoring enables immediate corrective measures, without waiting for laboratory results while an unsatisfactory product continues to be manufactured.
These types of real-time measurements present certain practical concerns not encountered in laboratory settings—such as the need for smaller, more reliable instruments; and for sample handling and excitation/detection techniques compatible with the surrounding production environment. For example, the sample may be continuously moving past the instrument on a movement path. The technique must be compatible with both the sample movement and the movement path.
In “bypass” configurations (where sample(s) from the production line may be diverted to proximate measurement stations)—stringent sample preparation is not practicable. The measurement technique must accommodate the sample “as is” and without any undue preparation.
An instrument must be small enough for installation into a manufacturing environment without impacting the surrounding production equipment. In general, the system must be smaller and simpler than most conventional x-ray diffraction systems, but with similar performance characteristics.
Such measurement environments, however, also offer certain benefits that often do not exist in laboratory environments. For example, the specific type of material under study is usually known; as is the specific material property of interest (e.g., phase or texture). The movement paths are also known, as are the material sampling and handling techniques.
What is required, therefore, are techniques, methods and systems which exploit the benefits of x-ray diffraction measurements in real-time production environments; which can endure the demanding conditions of these environments; and which also capitalize on some of the a-priori information associated with these environments.